There is a nearly unlimited quantity of designs of sandals employing a correspondingly wide variety of configurations of retention straps and means for adjustability to a wearer's foot.
Adjustability has commonly been achieved using laces or straps which are made adjustable by tying or by the incorporation of fasteners such as buckles, or hook-and-loop fasteners to allow varying the length of the straps or laces around the wearer's foot. Some designs, such as that shown in Scheinhaus et al, U.S. Pat. No. 4,200,997, have included a means of adjustability in which the securing straps pass freely through passages within the sole assembly of the sandal. A problem in this previous construction, where the webbing is continuous and freely adjustable is that the straps had a tendency to move readily relative to the sole assembly when the sandal was worn, causing some portions of the strap to loosen while other portions of the strap would tighten around the wearer's foot. This problem is common where the foot retention straps are subject to the uneven forces resulting from walking on uneven surfaces such as going up or down an incline and where these forces tend to cause the foot to move towards one side or one end of the sandal sole. This slippage of the straps where they pass through the sole assembly causes a poor retention of the foot and discomfort to the wearer.
Such a construction also has the disadvantage of adding unnecessary thickness and irregularities to the sole of the sandal under the wearers's foot due to the extra thickness of the tubing used to surround the strap where the strap passes through the sole of the sandal.
At the other extreme, straps fixed permanently in place would not allow adjustment of the various portions of the strap to the individual anatomy of a wearer's foot without having multiple buckles or other methods of adjustment. Such a construction presents the disadvantages of the straps not presenting a smooth surface against the wearer's foot and requiring numerous points and means of adjustment in order to achieve a good fit of the sandal on the wearer's foot.
With the growing popularity of outdoor recreation such as river-running in the desert canyons of the western United States where sandal type footwear is commonly used for its quick drying ability and where the same footwear may be used for hiking in rugged, uneven and hilly terrain along a river, it is desirable to use a sandal incorporating the features of the present invention.